Metallic plates used as interconnects between individual fuel cells of a solid oxide fuel cell can make the fuel cells quite heavy for aircraft flight applications. Interconnects may be made for example of stainless steel alloys. Solid oxide fuel cell systems fabricated from heavy gage, dense materials such as this are less attractive for long endurance aircraft propulsion applications because of their weight.
Stainless steel, while heavy, has other materials characteristics which make it suited for use in fuel cells. For example, stainless steel has resistance to hydrogen embrittlement (formation of hydrides), good resistance to oxidation, with fair creep strength and conductivity at temperatures above 800° C.
As a result, there is a need for a material to be used as a an interconnect in a solid oxide cell that has adequate structural and thermal/electrical conductivity characteristics at a lower weight than materials currently in use (such as stainless steel), while having adequate resistance to hydrogen embrittlement and oxidation.